Editing Breast imaging (section)

== '''Mammogram''' ==

** Situations where it is difficult to get images/interpret
*** <4cm breast tissue when compressed
*** Usually possible to get some images in a man, although not always, and not always useful
*** '''Sensitivity limited by breast density'''. Difficult to read in women <30yo. Useful only with high suspicion of malignancy in 30-40yo (start off with mammogram, then try MRI if too dense). Higher fat content is helpful for reading mammograms.
**** 95% sensitivity >60yo
**** 50% sensitivity <40yo
*** BIRADS classification for breast density:

**

*** Technique
**** Breast compression
***** Reduce the thickness of the tissue through which the radiation must pass
***** Separate adjacent structures
***** Improve resolution
**** Views
***** Typically mediolateral oblique (MLO) and craniocaudal (CC)
****** MLO needs to have visible pectoralis major
****** Note that the two views are not at right angles to one another
***** Magnification views to evaluate calcifications
***** Compression views to provide additional detail for mass lesions

** Suspicious findings:
*** Spiculated mass - 81% PPV

****

*** Non-calcified mass density (70% malignant if highly dense)
*** Grouped microcalcifications - likely intraductal calcifications in areas of necrotic tumours

****

*** Fine pleomorphic or linear branching microcalcifications - especially DCIS

****

** Low-energy x-ray: safe during pregnancy
** 10-15% of clinically evident breast cancers have a normal mammogram. 
** Screening mammography
*** Appears to be most effective for 60-70 year olds
***
** Interpretation

{| class="wikitable"
|'''Assessment'''
|'''Management'''
|'''Likelihood of cancer'''
|-
|Category 0: Incomplete – Need additional imaging evaluation and/or prior mammograms for comparison
|Recall for additional imaging and/or comparison with prior examination(s)
|N/A
|-
|Category 1: Negative
|Routine mammography screening
|Essentially 0% likelihood of malignancy
|-
|Category 2: Benign
|Routine mammography screening
|Essentially 0% likelihood of malignancy
|-
|Category 3: Probably benign
|Short-interval (6-month) follow-up or continued surveillance mammography
|>0 but ≤2% likelihood of malignancy
|-
|Category 4: Suspicious
|Tissue diagnosis*
|>2 but <95% likelihood of malignancy
|-
|Category 4A: Low suspicion for malignancy
|
|>2 to ≤10% likelihood of malignancy
|-
|Category 4B: Moderate suspicion for malignancy
|
|>10 to ≤50% likelihood of malignancy
|-
|Category 4C: High suspicion for malignancy
|
|>50 to <95% likelihood of malignancy
|-
|Category 5: Highly suggestive of malignancy
|Tissue diagnosis*
|≥95% likelihood of malignancy
|-
|Category 6: Known biopsy-proven malignancy
|Surgical excision when clinically appropriate
|N/A
|}

** BIRADS 3 should not be used in screening - needs further investigation, so technically a 0

** Mammogram classification - to allow detection of concordance within the triple test
*** M1: normal
*** M2: benign
*** M3: uncertain but probably benign
*** M4: suspicious and possibly cancer
*** M5: cancer
** Screening vs diagnostic mammography
*** Screening is just CC and MLO
*** Diagnostic would be where the radiologist is available and specific views are obtained to achieve better resolution on abnormalities, including magnification, compression, lateral
*** Tomography